import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        int n = in.nextInt();
        in.nextLine();
        String str = in.nextLine();
        int countS = 0,countSh = 0,countShy = 0;
        for (int i = 0; i < n; i++) {
            char c = str.charAt(i);
            if(c == 's') countS ++;
            else if (c == 'h') {
                countSh ++;
            } else if (c == 'y') {
                countShy ++;
            }
        }
        long x = (long) countS * countShy * countSh
        System.out.println(x);
    }
}